A Cleveland man recently released from prison is charged with the murders of his prison pen pal and her boyfriend, reports Cleveland 19.

Parma Heights Police Det. Steve Scharschmidt says that Thomas Knuff, 42, was released from prison April 11 after having served 15 and a half years for multiple charges, including aggravated robbery.

The bodies of Regina Capobianco and John Mann were found on June 21, a month after Capobianco was reported missing on May 23. The two had been stabbed to death.

Capobianco and Knuff reportedly became pen pals while they were both behind bars. They wrote letters to each over the course of 10 years. She and Mann, who had met at a Strip Club where Mann regularly visited, came to pick up Knuff when he was released from prison.

Police arrested Knuff on May 31 and asked him where his former pen pal was. Capobianco and Mann’s bodies were later found in a house on Newland Road where they had been rotting for five weeks.

Thomas Knuff/Parma Heights Police

Both had been stabbed multiple times in their neck and shoulders.

Parma Heights Police Chief Daniel Teel said that it was hard for the officers that discovered the bodies and handled the crime scene, reports Cleveland.com.

“For many of them this is one of the toughest crime scenes our detectives have had to deal with. Not only because of the crime, but because of the time and the conditions that the victims were found in.”

He believed it may involve drugs. According to the detective, there have been multiple reports of “drug activity and high traffic” at the house on Newland Road. He says there have been several investigations at the house involving drugs and prostitution.

Knuff was charged with two counts of aggravated murder for the deaths of Capobianco and Mann. He was held on a $25 million dollar bond for each charge at his arraignment on Monday. In addition to the murder charges, Knuff was also charged with two unrelated breaking and entering charges, for which he was held on a $10,000 bond.